The present invention relates to a sliding member formed of fiber-reinforced metal.
Conventionally, resin has been mainly used as the matrix of fiber reinforced material. However, the mechanical strength and heat resistance of the matrix of resi are insufficient. Therefore, the development of the fiber reinforced metal containing a metallic matrix has been required.
A sliding member which is in sliding contact with an opposite member, is required to have high mechanical strength and excellent heat resistance. And in the sliding member, the difference between the coefficient of thermal expansion of the sliding member and that of the opposite members, is a serious problem.
Hereinafter, vanes of a sliding vane compressor will be explained as one example of the sliding member. In the conventional compressor, a liner portion and a liner side portion defining a fluid chamber are made of iron-based material such as cast iron, and the vanes travelling within the fluid chamber while sliding on the liner portion and the liner side portion are made of an aluminum alloy such as aluminum-silicon alloy.
However, the aluminum alloy has a coefficient of thermal expansion larger than that of iron. When the compressor is driven at a high speed and high load, the vanes are heated to a high temperature so as to expand. As a result, the vanes are locked in the liner portion and the liner side portion. Therefore, the clearance between the vanes and the liner portion and that between the vanes and the liner side portion must be set large so as to prevent the vanes from being locked in the liner portion and the liner side portion. Consequently, the compression efficiency of the fluid is lowered.
Accordingly, one object of the present invention is to provide a sliding member formed of carbon fiber-reinforced metal of which the coefficient of thermal expansion is adjusted so as to be substantially equal to that of the opposite member.